Robertson Lucy, Sylvester Karl Peter, Newman Joseph
Royal Papworth Hospital, Respiratory Physiology Department, Cambridge, UK.
Lung Function Unit, Cambridge University Hospitals, Cambridge, UK.
ERJ Open Res. 2025 Jun 2;11(3). doi: 10.1183/23120541.00891-2024. eCollection 2025 May.
The 6-min walk test (6MWT) oxygen desaturation is an indication for ambulatory oxygen therapy (British Thoracic Society (BTS), peripheral oxygen saturation ( ) <90%; American Thoracic Society (ATS), ≤88%). Shorter walk test durations may be beneficial in remote monitoring or in severe interstitial lung disease (ILD), where completing a 6MWT is challenging.
Retrospective routine clinical 6MWT with minute interval , lung function and mortality data were collected from patients with ILD. Median lowest at different time periods of the 6MWT were compared statistically and prognostically. Patients were classified by the Distance-Oxygen-Gender-Age-Physiology (DO-GAP) index.
274 patient records were analysed. The median values recorded at 0-1, 1-2, 2-3, 3-4, 4-5 and 5-6 min of the 6MWT were 96%, 93%, 92%, 92%, 91.5% and 91%, respectively (p<0.001). Prognostically, the areas under the curve (AUC) for predicting 3-year mortality were significant (p<0.001) and similar for the minimum between 0-1, 1-2, 2-3, 3-4, 4-5 and 5-6 min (AUC 0.71, 0.76, 0.77, 0.76, 0.77 and 0.76, respectively). 111 patients desaturated to <90% (BTS criteria) during the 6MWT, with the median time to desaturation ranging from 1.5-2.5 min between DO-GAP groups (p=0.01). 94 patients desaturated to ≤88% (ATS criteria) during the 6MWT, with the median time to desaturation ranging from 1.5-2.2 min between DO-GAP groups.
Exertional desaturation manifests during earlier stages of the 6MWT. A 3-min walk has 87-91% sensitivity in detecting oxygen desaturation requiring ambulatory oxygen therapy, while retaining prognostic value. Shorter walk durations can efficiently detect desaturation in ILD, making it more patient-centred and feasible for remote testing.
6分钟步行试验（6MWT）中的氧饱和度下降是进行门诊氧疗的指征（英国胸科学会（BTS），外周血氧饱和度（ ）<90%；美国胸科学会（ATS）， ≤88%）。较短的步行试验时长可能有利于远程监测或在严重间质性肺疾病（ILD）中，因为完成6MWT具有挑战性。
从ILD患者中收集回顾性常规临床6MWT数据，包括每分钟间隔的 、肺功能和死亡率数据。对6MWT不同时间段的最低 中位数进行统计学和预后比较。根据距离-氧-性别-年龄-生理学（DO-GAP）指数对患者进行分类。
分析了274例患者记录。6MWT在0 - 1、1 - 2、2 - 3、3 - 4、4 - 5和5 - 6分钟记录的 中位数分别为96%、93%、92%、92%、91.5%和91%（p<0.001）。在预后方面，预测3年死亡率的曲线下面积（AUC）具有显著性（p<0.001），且在0 - 1、1 - 2、2 - 3、3 - 4、4 - 5和5 - 6分钟之间的最低 的AUC相似（分别为0.71、0.76、0.77、0.76、0.77和0.76）。111例患者在6MWT期间血氧饱和度降至<90%（BTS标准），DO-GAP组之间血氧饱和度下降的中位时间为1.5 - 2.5分钟（p = 0.01）。94例患者在6MWT期间血氧饱和度降至≤88%（ATS标准），DO-GAP组之间血氧饱和度下降的中位时间为1.5 - 2.2分钟。
运动性氧饱和度下降在6MWT的早期阶段就会出现。3分钟步行在检测需要门诊氧疗的氧饱和度下降方面具有87 - 91%的敏感性，同时保留预后价值。较短的步行时长可以有效检测ILD中的氧饱和度下降，使其更以患者为中心且便于远程测试。
